This invention relates generally digital cameras to and more specifically to a device used to control a cursor position on a display on a digital camera.
Digital still cameras and digital video cameras often include a multipurpose display on the back of the camera. The display may be used to show one or more images, or the display may be used for various control functions. For example, multiple reduced size (xe2x80x9cthumbnailxe2x80x9d) images may be arranged on the display so that a camera operator may select an image for viewing, or for transmission to a storage device or computer. Alternatively, a camera may include various image editing functions, so that areas of an image need to be selected for editing. Alternatively, the display may present a menu of camera control functions, and the camera operator may need to scroll through and select various control choices. Typically, selection of one image from an array of images, or defining an area for editing, or selection of one choice from a menu of items, requires movement of a cursor over the image or menu item to be selected, followed by pressing a key or button to initiate the selection. In general, just as cursors are controlled for computer displays, a cursor in a digital camera may be controlled, for example, by a mouse, up/down control buttons, levers (xe2x80x9cjoystickxe2x80x9d), a track-ball, rocking platform switches, or touch sensitive pads that track finger movement. However, each of these cursor control devices require extra parts, and require space on the surface of the camera or appendages to the camera. In addition, some devices requiring discrete movements, such as rocker switches, may be less intuitive to an operator compared to devices that use continuous movement, such as a mouse, which people are accustomed to using with computer displays. Small cameras may have very limited space for controls. There is a need for simple low-cost cursor control, with continuous control similar to use of a mouse, without requiring devices that consume space on the surface of the camera.
The array of photosensors used for imaging is used to detect pressure, for example pressing by a finger, on an attached lens cap. The location of the pressure may be used to directly position a cursor, or the location of the pressure may be used to control direction of movement of a cursor. As a result, using the lens cap for cursor control closely mimics touch pad pointing devices, providing continuous position or motion control. The lens cap, for example, may comprise two layers that are separated. The inside layer may be a rigid, translucent, dark colored material. The outer layer may be flexible and light colored. When the outer layer is pressed against the inner layer, the reflectance on the inner surface at the point of contact with the light material becomes much higher than the reflectance where there is no contact with the light colored material. Alternatively, the lens may enclose a liquid so that the color normally seen by the array of photosensors is the color of the liquid. Then, when the outer layer of the lens cap is depressed, a small area of the outer layer displaces the liquid and touches the inner layer, so that the a color of the small area seen by the array of photosensors is the color of the outer layer of the lens cap. Alternatively, thermally sensitive materials may be used, so that the lens cap changes color in an area pressed by a relatively warm finger.